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RE: Tegenaria agrestis
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Helsdingen, P.J. van
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Apr 27, 2009 00:07 PDT
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The whole story about Tegenaria agrestis being harmfull to humans is a
well-known HOAX!
Peter van Helsdingen
P. J. van Helsdingen
European Invertebrate Survey - Nederland
European Invertebrate Survey - International
National Museum of Natural History
Darwinweg 2, 2333 CR Leiden, Netherlands
P.O. Box 9517, 2300 RA Leiden, Netherlands
tel.: (0031) 71 56 87 413 or (0031) 06 51058720
fax: (0031) 71 56 87 456
E-mail: helsd-@nnm.nl
http://www.naturalis.nl/eis <http://www.naturalis.nl/eis>
http://www.european-arachnology.org/reports/fauna.shtml
<http://www.european-arachnology.org/reports/fauna.shtml>
P denk aan het milieu - dit mailtje printen is niet altijd nodig
"There is grandeur in this view of life" (Darwin 1859)
Van: Zach Valois [mailto:OutLande-@yahoo.com]
Verzonden: zaterdag 25 april 2009 18:44
Aan: arach-@topica.com
Onderwerp: Re: Tegenaria agrestis
Interesting work Greta, I recall speaking with Warren Savary about your
work on this during our last sampling trip together.
Perhaps I will get out and try to collect some of these. Does anyone
have any specific locations for them in Utah?
Zachary J. Valois
Salt Lake City, Utah
Z_Va-@yahoo.com
--- On Sat, 4/25/09, Greta Binford <binf-@lclark.edu> wrote:
From: Greta Binford <binf-@lclark.edu>
Subject: Re: Tegenaria agrestis
To: arach-@topica.com
Date: Saturday, April 25, 2009, 9:37 AM
Hello all,
Melissa Gaver is working on Tegenaria agrestis for part of her
Ph.D. work. What
I did was a comparative analysis between Pacific Northwest T.
agrestis and
European T. agrestis because I thought it was interesting that
there were never
any reports of clinical issues associated with their venoms in
Europe. I was
curious to know if there were unique chemicals in the US
populations or if I
could find some other difference between the two (habitat,
proximity to humans,
etc). I did not find evidence of chemical difference between US
and European
populations, but I did find striking differences between sexes
within
populations. I also did not find any differences in insecticidal
potency between
the populations. This is all published in a manuscript that is
available at my
website http://www.lclark.edu/~binford/ . As a side project for
that work I sent
spiders and venoms to Hernan Gomez who injected venom from
European and N.
American T. agrestis males and females into rabbits (the same
strain used by
Darwin Vest). We also tried to get the spiders to bite rabbits.
We could not get
the spiders to bite, even by harassing them and pressing their
chelicerae
against shaved rabbits. Furthermore all of the injections
produced nothing more
than a red bump. We did not publish this because sample sizes
were low. As far
as I know that's the current state of understanding.
Discover magazine wrote a nice article about this issue in 2005
or 2006. I
don't think the story has changed since that article came out.
Greta
On Apr 25, 2009, at 8:06 AM, Chuck Kristensen wrote:
>
> Hi Zachary,
>
> I have not heard of any definitive results and I do not know
of anyone
> who is looking or is even interesed in looking at this
seriously now. As
> I recall, Darwin was only able to get a little necrosis in a
couple New
> Zealand white rabbits (but not in a few other animals), Greta
Binford
> did not detect Loxosceles-style sphingomyelinase D in T.
agrestis and
> another bioassay only came up with very weak inflammatory
activity.
>
> This could be a difficult project. Even if the activity does
exist, it
> might take years to find a validate a suitable animal model
and/or
> cell-based assay and the project could be even more
complicated if the
> toxin(s) is unstable or if they only produced by one gender at
a certain
> age or under specific enviromental conditions.
>
> We maintained a colony of Tegenaria agrestis from Salt Lake
City several
> years ago, but were not able to generate much interest in the
venom and
> eventually let the colony go senile and die off of old age
without
> breeding.
>
> We would like to start up another colony sometime soon and
have been
> asking for live specimens from collectors. Their venom isn't
even
> available for research now.
>
> Very best,
> Chuck
> Spider Pharm
> http://www.spiderpharm.com
>
> outlande-@yahoo.com wrote:
>> Thanks guys,
>>
>> I myself become overwhelmed with spider identifications this
time of
>> year here in Utah. Every other person thinks their home is
infested
with
>> brown recluse spiders or what not. I had been curious about
true
>> toxicity levels of T. agrestis.
>>
>> thanks Rick
>>
>> Zachary J. Valois
>> Salt Lake City, Utah
>> Z_Va-@yahoo.com
>>
>> --- On Fri, 4/24/09, Rick West <rickc-@shaw.ca> wrote:
>>
>> From: Rick West <rickc-@shaw.ca>
>> Subject: RE: Tegenaria agrestis
>> To: arach-@topica.com
>> Date: Friday, April 24, 2009, 8:34 PM
>>
>>
>>
>> #yiv368161522 .hmmessage P {
>>
PADDING-RIGHT:0px;PADDING-LEFT:0px;PADDING-BOTTOM:0px;MARGIN:0px;PADDING
-TOP:0px;}
>>
>> #yiv368161522 {
>> FONT-SIZE:10pt;FONT-FAMILY:Verdana;}
>>
>>
>> Hi Kelly,
>>
>> I didn't notice your posting on this forum until after it was
sent.
>> Please excuse the
>> previous typos everyone (corrected below). I suspect Robb's
email
was
>> not noticeable
>> in the reply. I recommend you contact him directly
>> at; Robb.B-@gems6.gov.bc.ca
>>
>> Hope this helps, Rick
>>
>>
>>
>> From: Rick West [mailto:rickc-@shaw.ca]
>> Sent: Friday, April 24, 2009 7:09 PM
>> To: arach-@topica.com
>> Cc: Robb Bennett (Robb Bennett)
>> Subject: RE: Tegenaria agrestis
>>
>>
>>
>> Hi Kelly,
>>
>> Allow me to refer you to a local authority on T. agrestis -
Dr. Robb
>> Bennett. The majority
>> of local spiders brought in by paniced arachnophobes aren't
even
capable
>> of penetrating
>> human skin with their bite. Of those that can, its believed
that
>> bacteria around the mouth
>> and fang region may be responsible for many of the neucrotic
>> lesions seen in patients.
>> These people may be more sensitive to particular bacteria
that enter
the
>> bite site ... if it
>> was, in fact, caused by a spider at all.
>>
>>
>>
>>
>
>
>
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